In changeset 88b6ef9aa9e9, a new function ported_lib() was added that crashes on error reporting in Py3 because it tries to do this:

    raise RuntimeError("Benchmark died: " + err)

"err" is a bytes object that comes straight from the subprocess pipe.

The reason why I noticed this is because the new function assumes that it can run "python" with the "-c" option and pass an arbitrary Python command string. That may not be true if it is actually executing some wrapper script (as we do for Cython, for example). Currently, the only requirement for the external Python command is that it can run a Python script that it receives on the command line. We shouldn't unnecessarily extend that interface.

I'm not sure how to best fix this, but the only way I can currently see is to run an external Python script that prints the requested information.